PP (Polypropylene)

Description

PP (Polypropylene) per ISO 1873-1 is a semi-crystalline polyolefin with density 0.90-0.91 g/cm3 — the lightest structural polymer. Excellent chemical resistance, good fatigue resistance (outstanding integral hinge life), low cost. Continuous service to 100-130 C depending on grade. Widely used for automotive bumpers, packaging, medical syringes, laboratory equipment and water pipes (PP-R).

Key Properties — Homopolymer (PP-H, rigid)

Rm (Tensile Strength)

30 – 40

MPa

Re / Rp0.2 (Yield)

25 – 35

MPa

A₅ (Elongation)

≥ 100.0

E (Young's Modulus)

GPa

Density

0.91

g/cm³

Main Designations (18)

Standard Body	Designation	Country / Region	Note
ISO	PP (ISO 1873-1/2)	International
EN	EN ISO 1873	European Union
ASTM	D4101 PP	USA
DIN	DIN 16742 / EN ISO 1873	Germany
Trade Names	Moplen (LyondellBasell) / Novolen (INEOS) / Bormed (Borealis) / Hostalen PP (LyondellBasell)	Global
Pipe Grade	PP-R (ISO 15874) — pressure piping for hot/cold water	International	Standard for plumbing in SE Europe
Pipe Grade	PP-B (block copolymer) — industrial piping	International
UL	94 HB (standard) / 94 V-0 (FR grades)	USA
JIS	PP (JIS K 6921-1/2)	Japan
GOST	Polipropilen (PP)	Russia / CIS
FDA	21 CFR 177.1520 (food and drug contact)	USA	FDA approved — widely used for food packaging and medical
JUS	PL-PP	Yugoslavia / Serbia	Polypropylene engineering plastic; JUS G.S2.040
RoHS	Compliant	EU
Supply Forms	Sheet, rod, pipe (PP-R), plate + injection/extrusion moulding compound	Global
ISO	PP (ISO 1873-1 homopolymer)	International
Trade Names	Moplen (LyondellBasell) / Borpact (Borealis) / Novolen (INEOS)	Global
UL	94 HB standard; V-2/V-0 with FR additive	USA
FDA	21 CFR 177.1520 (food contact)	USA

Standards (18)

#	Standard Body	Designation	Country / Region	Note
1	ISO	PP (ISO 1873-1/2)	International	—
2	EN	EN ISO 1873	European Union	—
3	ASTM	D4101 PP	USA	—
4	DIN	DIN 16742 / EN ISO 1873	Germany	—
5	Trade Names	Moplen (LyondellBasell) / Novolen (INEOS) / Bormed (Borealis) / Hostalen PP (LyondellBasell)	Global	—
6	Pipe Grade	PP-R (ISO 15874) — pressure piping for hot/cold water	International	Standard for plumbing in SE Europe
7	Pipe Grade	PP-B (block copolymer) — industrial piping	International	—
8	UL	94 HB (standard) / 94 V-0 (FR grades)	USA	—
9	JIS	PP (JIS K 6921-1/2)	Japan	—
10	GOST	Polipropilen (PP)	Russia / CIS	—
11	FDA	21 CFR 177.1520 (food and drug contact)	USA	FDA approved — widely used for food packaging and medical
12	JUS	PL-PP	Yugoslavia / Serbia	Polypropylene engineering plastic; JUS G.S2.040
13	RoHS	Compliant	EU	—
14	Supply Forms	Sheet, rod, pipe (PP-R), plate + injection/extrusion moulding compound	Global	—
15	ISO	PP (ISO 1873-1 homopolymer)	International	—
16	Trade Names	Moplen (LyondellBasell) / Borpact (Borealis) / Novolen (INEOS)	Global	—
17	UL	94 HB standard; V-2/V-0 with FR additive	USA	—
18	FDA	21 CFR 177.1520 (food contact)	USA	—

All values in wt.%

Carbon (propylene repeat unit)

~85.7000

Hydrogen

~14.3000

H2O

Water absorption (any condition)

≤ 0.0200

Element	Symbol	Min %	Max %	Typical %
Carbon (propylene repeat unit)	C	—	—	85.7000
Hydrogen	H	—	—	14.3000
Water absorption (any condition)	H2O	—	0.0200	—

Mechanical Properties

Condition	Code	Rm min MPa	Rm max MPa	Re min MPa	Re max MPa	A₅ min %	Z %	KV J	HB min	HB max	HRC min	HRC max	E GPa
Homopolymer (PP-H, rigid)	PPH	30	40	25	35	100.0	—	—	—	—	—	—	1.5
Block Copolymer (PP-B, tough)	PPB	25	35	20	28	300.0	—	—	—	—	—	—	1.3
Random Copolymer (PP-R, soft)	PPR	20	30	15	25	300.0	—	—	—	—	—	—	1.0
PP GF30 (glass-filled)	GF30	80	100	60	80	3.0	—	—	—	—	—	—	5.5

Physical Properties

Density

0.905

g/cm³

Melting Point

160–165

°C

Young's Modulus

1.5

GPa

Poisson's Ratio

0.430

—

Thermal Conductivity

0.2

W/m·K

Thermal Expansion

130.00

×10⁻⁶ /K

Specific Heat

1,800

J/kg·K

Magnetic

Heat Treatment

No heat treatment required

Medium:N/A

Duration:N/A

Cooling:N/A

Hardness After:N/A

PP is a thermoplastic — no conventional heat treatment. Join by hot gas welding, butt fusion welding (PP-R pipes) or adhesive bonding.

PP-R Pipe Butt Fusion Welding

Temperature:210°C – 220°C

Medium:Heated plate / butt fusion

Duration:Per pipe diameter (EN ISO 21307)

Cooling:Controlled cool

Hardness After:Full fusion

Standard method for PP-R plumbing and process pipe installation. Pressure-rated joints.

Machinability

Machinability Rating

relative to AISI B1112 = 100%

350.0%

Excellent

Turning Speed (HSS)

600

m/min

Turning Speed (Carbide)

2,000

m/min

Feed Rate (Turning)

0.800

mm/rev

Drilling Speed (HSS)

550

m/min

Milling Speed (Carbide)

2,000

m/min

Coolant	Compressed air; light mist or dry; no flood water coolant
Chip Formation	Medium-long chips; gummy at high speed; chip control challenging
Tool Material	Carbide K10 or HSS M2; sharp tools; positive rake angle; good chip evacuation
Surface Finish	Ra 0.8-3.2 um

Good machinability — especially PP-H. PP tends to melt rather than cut at high speeds. Use low cutting speed, sharp tools, high rake angle and good chip evacuation. Chips are waxy and can redeposit on surface.

Applications

Packaging

Food and beverage containers, caps, closures, yogurt pots and film packaging.

Automotive

Bumper fascias, door panels, battery cases, fluid reservoirs and carpet fibres.

Plumbing

PP-R hot/cold water plumbing pipes (ISO 15874) — widely used in residential construction across SE Europe.

Medical

Syringes, IV bags (film), laboratory ware, specimen containers and disposable surgical instruments.

Chemical Equipment

Tanks, pipe fittings, valve bodies and laboratory equipment for chemical service.

Packaging

Food containers, yoghurt tubs, bottle caps, detergent containers and flexible packaging.

Automotive

Battery cases, bumpers, door panels, cable conduit and under-bonnet components.

Medical

Autoclavable device housings, syringe barrels and medical packaging.

Chemical Piping

PP-R pipe for hot and cold water and chemical service.

Consumer

Living hinge containers, chairs, luggage and storage boxes.

Technical Notes

✅

PP-R Plumbing

PP-R pipes and fittings (ISO 15874) are widely used for hot and cold water plumbing in BiH and SE Europe, replacing copper. Joined exclusively by heat fusion (socket or butt) — creating monolithic joints with full pipe-wall strength. Operating temperatures up to 60 C at 10 bar (PP-R PN10).

✅

Integral Hinge

PP has outstanding fatigue resistance to repeated flexing at the hinge line (integral or live hinge). A 0.3-0.5 mm PP web will survive millions of flexing cycles — unmatched by any other plastic or metal. Standard for one-piece hinged containers (Tic-Tac lids, etc.).

💧

Chemical Resistance

Very good resistance to acids, bases, alcohols and polar solvents. NOT resistant to: aromatic and halogenated hydrocarbons (swell/dissolve), oxidising acids and strong oxidising agents. Similar to HDPE but slightly better heat resistance.

✅

PP vs PE vs ABS

PE: better chemical resistance, lower stiffness, lower cost. PP: HDT 105 C (vs 80 C for PE), better stiffness (1.6 vs 1.1 GPa), living hinges possible. ABS: better impact, better finish, lower chemical resistance. PP is the default for chemical-resistant, autoclavable, cost-sensitive applications.

💡

Living Hinge

PP is the only common plastic that can form living hinges -- thin sections surviving millions of flex cycles. Molecular chains align parallel to hinge axis during first flex post-moulding. PP flip-top bottle caps use this every day.